The invention relates to an apparatus and a method for the packaging of articles in bags.
In a known apparatus for the packaging of articles (EP 816 225) alternately acting sliders are present, which are moved backwards and forwards. During the rearwards movement in each case one slider is moved out of the path of the other slider. The slider movement is freely programmable (slider insertion and removal positions, slider strokes, movement profiles).
The articles to be packaged can in many cases be stacks of flat objects. As a result of the nature of the packaging with laterally inserted side folds, with respect to the packaging cross-section one is bound to specific geometrical conditions. The pack cannot be higher than it is wide. This circumstance exists with products having a limited content.
The flat objects are supplied vertically as a result of the design of the apparatuses with which said flat individual objects are finished. If there is a drop below the height/width ratio in the pack, the articles must be placed horizontally. The objects are frequently compressed articles, e.g. slip inserts, cleaning cloths or other fleecy or fluffy products.
For reducing the packaging volume and for improving the appearance of the finished pack, said formations have to be compressed.
The problem of the invention is to propose a method and an apparatus for the packaging of articles in bags, which operates with considerable reliability and provides the possibility of reducing the effects of disturbances.
To solve this problem the invention proposes an apparatus and a method having the features described below.
The invention is incorporated in an apparatus that uses a slider, which as the upper slider is fixed to a revolving chain. Therefore, the slider is not moved backwards and forwards and instead moves along a closed path, the return path taking place at a different height. The product slider sliding path is fixed. The slider initially brings the article to be packed into the filling magazine, from where the article is brought into the bag station. From there it is brought to the sealing station with the aid of the accompanying magazine.
In the transfer station the filled bag can in this way be carefully conveyed, without the pack being influenceable by slots, slits or other projections.
According to a further development of the invention, the packaging magazine is arranged and constructed in such a way that the slider in the infeed position can slide an article to be packed into the magazine.
According to a further development, the packaging magazine is movable in such a way that it moves together with the article to be packed into an opened bag and is left standing there in the transfer position. Thus, the sliding in of the article to be packed takes place with it still located in the packaging magazine. Thus, also here the article can be guided and therefore protected by the packaging magazine. The packaging magazine can have smooth side walls, a smooth bottom and also a smooth top side with a slot for the slider. Optionally an air cushion can also be formed.
According to a further development of the invention, the movement path of both magazines can overlap. Therefore the transfer magazine can be moved to a point where the packaging magazine can also be located, but there is no need for a complete overlap of both magazines.
According to another further development of the invention, the two magazines can be simultaneously in the transfer position and can consequently also overlap. As a result there can be a careful transfer with a limited lateral clearance of the filled bag from the packaging magazine into the transfer magazine. In the position where both magazines are moved out of the transfer position, they have such a mutual spacing that the bag station can open a bag unhindered by the magazines.
The overlap can e.g. result from the fact that the transfer magazine has a somewhat greater width and height than the packaging magazine, so that the latter can partly move into the transfer magazine. This construction is preferred, even though a reverse construction is also possible.
According to another further development of the invention, in the sealing position the transfer magazine can be positioned in such a way that the slider has slid the packed article through the sealing jaws of a sealing station.
According to a further development of the invention, the transfer magazine can be constructed in such a way that it guides the filled bag during its movement to the sealing station. This guidance can take place through smooth side walls, a smooth, flat bottom and a smooth top side. It can in particular be provided that the bottom and the side walls, together with the magazine, are guided over and beyond any gaps, slots or other parts of the sealing station, so that the filled bag cannot stick or be held up at any point. The filled bag is then stopped at a point beyond any gaps, whereas the slider and the transfer magazine are then moved back. The bag with its content is then located on the opposite side of the sealing jaws. The joining of the still open bag can then take place with the aid of the welding jaws or dies. It is also possible to produce an air cushion, also on sliding the bag out of the transfer magazine, in order to simplify or aid the sliding out process.
According to another development of the invention, during its movement in the conveying direction, the transfer magazine is moved more slowly than the slider, so that during the entire transfer magazine movement it moves the filled bag through the magazine.
The invention is particularly advantageous if the article to be packaged is a compressible article, which is slid into the bag under a certain tension. This tension is to be maintained. It can in particular be a stack of objects, where also the gaps between the objects are to be compressed.
In the description up to now reference has been made to a single slider. It is obviously appropriate for there to be several sliders on the revolving mechanism in order to increase the output of the apparatus.
If the articles to be packed are stacks of fluffy objects, according to the invention a row of juxtaposed, vertically positioned objects is formed. As soon as the collecting magazine is filled, it is pivoted from the filling position into the emptying position, where the objects rest flat on one another. They are compressed by the compressing device, which constitutes a type of precompression. The air between the individual objects and the air within said objects is displaced. In said compressed position the stack can be removed from the rotary magazine.
According to a further development of the invention, the compressing device has a displaceable pressure wall, which is placed approximately parallel to the flat sides of the objects and is movable perpendicular to said flat sides. Thus, in the filling position the pressure wall is parallel to a side wall, whereas in the emptying position it is parallel to the bottom, because during pivoting the magazine changes its orientation in the same way, e.g. by 90xc2x0. What was originally a side wall, becomes the bottom or top in the emptying position.
In a further development of the invention compression takes place during the pivoting of the collecting magazine. This can e.g. take place in that the movement of the pressure wall takes place in forcibly controlled manner, e.g. by a cam, a curved guide or the like.
However, it is also possible for the movement of the pressure wall and therefore the compression of the flat objects to take place with the aid of a servomotor, which is then also preferably forcibly controlled, e.g. by an electronic control.
The drive for the pivoting device can preferably also have a servomotor, in order to precisely control the residence of the magazine in each of the two positions.
The invention more particularly proposes that the apparatus has several magazines. It can e.g. be the case that one of the several magazines is in the filling position and a second magazine is in the emptying position.
According to a further development of the invention, the emptying of one magazine and the filling of another magazine can take place simultaneously. For this purpose the positions can be so displaced from a line that the two positions do not interfere with one another.
According to the invention, the pivoting device can pivot in reciprocating manner the collecting magazine or the several collecting magazines.
It is also possible and is proposed by the invention, that the pivoting device is constructed in such a way that it gradually rotates in one direction the at least one collecting magazine.
The method proposed by the invention proceeds in the following way. An article to be packed is slid into a packaging magazine. The packaging magazine together with the article located therein is moved into an opened bag. During this movement optionally it is possible to displace the article with respect to the packaging magazine. The packaging magazine can e.g. be slid into the bag to such an extent that its front side in the conveying direction comes onto the bottom of the bag. The object is slid into the bag by the magazine. The filled bag is then transferred into the transfer magazine and the packaging magazine is extracted from the bag. In the transfer magazine the filled bag is slid to a sealing station where it is sealed.
According to a further development of the invention the packaging magazine is reciprocated between an infeed position and the transfer position.
A revolving slider is used for sliding the article and preferably several revolving sliders are arranged in succession.
The transfer magazine is moved backwards and forwards between the acceptance position and the sealing station.
According to a further development, the transfer magazine is moved more slowly in the conveying direction than the filled bag. As a result the filled bag is moved through the transfer magazine, i.e. is slid.
During the movement of the filled bag the latter is guided on all sides, so that at no point can it stick.
The packaging magazine and the transfer magazine can be simultaneously located at the acceptance position.
If the articles to be packed are stacks of fluffy, flat objects, which are delivered in the vertical position, the invention proposes that these vertical objects be arranged in juxtaposed form for forming a stack and after the formation of the stack pivoting takes place in such a way that the flat objects rest on one another. The stack is then compressed in that the flat sides of the outer objects are moved towards one another. The thus formed compressed and horizontally positioned stack can then undergo further packaging.
The invention proposes that the stack is compressed after the start of pivoting and prior to stack removal.
The invention more particularly proposes that the stack be compressed during pivoting and preferably during the entire pivoting process.
Compression can take place in that a pressure wall is located in the magazine, which at the start of compression is positioned laterally and during magazine pivoting changes its position together with the magazine, so that at the end of pivoting it forms the magazine bottom.
According to the invention simultaneously two stacks can be formed in each magazine.